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Dan, Auto Technician
Category: Chevy
Satisfied Customers: 3490
Experience:  GM Mark of Excellence/ Service Guild Participant with 13 years experience, ASE Master Certified
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My suburban engine is making a loud ticking noise. The oil ...

Customer Question

My suburban engine is making a loud ticking noise. The oil pressure,oil level and tempiture all all good. But it does not have the power it should. I just had a new head gasket put in it last week because it was leaking prestone. It run great before they fixed the gasket. Any ideas what could of happened?
Submitted: 8 years ago.
Category: Chevy
Expert:  Dan replied 8 years ago.
My best theory is the leaking coolant inside the engine probably did what is called "washing the bearings". This involves coolant getting into the engine oil and thinning it out to the point the oil no longer lubricates but rather just flows thru the bearings and passages. And because there is no lubricating the engine develops ticks, knocks or even worse total catastrophic failure by seizing up. When the bearings are washed like this if the engine has over 100,000 miles I highly recommend replacing the engine assembly with a good used engine with low mileage or a remanufactured engine from a reputable supplier. It would come with a good warranty on parts and labor.
Dan and 3 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
Should'nt the repair shop of change the oil or at least told me to?
Expert:  Dan replied 8 years ago.
Yes they probably changed the oil but the damage to the bearings may have already occured before they got the vehicle and the head gaskets were leaking. We actually ran into this very thing with a Corvette that came into our shop with an obviously blown head gasket. We replaced the gaskets, had the cylinder heads checked and resurfaced and reassembled the engine. After we got it back together and running the engine would make an intermittent tick and/or knocking especially at idle. Same thing, coolant was in the oil prior to us working on the engine and washed out the bearings causing the tick or knock. Even though we fixed the overheating and didn't cause the tick/knock the BAR (bureau of automotive repair) heard from the customer their side of the story and basically made us pay him back because we didn't fully disclose the possibiltity of this happening (even though it wasn't our fault). We now warn customers and if at all possible try to either sell them a new engine or turn away the job.
Customer: replied 8 years ago.
Thank You,
Expert:  Dan replied 8 years ago.
You are welcome and thanks for using JustAnswer. Good luck.